Create new CodePlex project from branch?

We need to "fork" an existing CodePlex project, but we want to make it easy to get changes to and from the original trunk project. We expect a lot of collaboration, yet we need them to be independent. Can we create a new CodePlex project
whose source is a branch of the other? This doesn't seem possible, since the tfs uri's are different -
tfs04.codeplex.com vs tfs08.codeplex.com. Both teams are using VS Team Explorer.

If there's any way to accomplish what we are trying to do, please let me know. I'm open to other solutions.